1. Field of the Invention
The invention relates to infant car seats for seating and transporting infants and small children.
2. Description of the Related Art
Infant car seats are commonly used to conveniently and safely seat and transport infants and small children. Such car seats generally comprise a molded plastic seat shell having a seat back for supporting the infant and a U-shaped handle that extends across the seat shell for carrying the seat shell. A safety belt harness is typically provided to secure the infant in the seat shell.
One problem with conventional car seats is that they cannot be adjusted to fit the size of the infant as the infant grows. The car seat becomes uncomfortable for the infant and can pose an increased risk of injury to the infant in a vehicle collision if the safety belt harness does not fit properly. Accordingly, some existing car seats have an adjustable seat back that can be extended relative to the seat shell as the infant grows. This allows the car seat to be better fitted to the infant. The adjustment of the seat back in such car seats, however, is typically complicated and time consuming. In addition, improper adjustment of the seat back can result in injury to the infant.
In conventional car seats, the safety belt harness typically includes a number of safety belts that extend from behind the seat shell through slots in the seat back. If the seat back is movable to fit the infant, the safety belts typically must be removed and re-threaded through the slots in the seat back after the seat back is adjusted. This, too, can sometimes be difficult and time consuming.
Young infants do not have the physiological development of the neck, shoulders, and spine necessary to be restrained by a safety belt harness in a forward facing direction without serious injury. Accordingly, in order to better protect infants in the event of vehicle collisions, infant car seats are designed to face rearwardly in a direction opposite the normal direction of travel of the vehicle. In rear-facing car seats, collision impact forces are distributed by the seat back over the infant's entire head and torso, thereby minimizing the risk of injury to the infant.
In general, the more upright the seat shell, the better the distribution of collision impact forces over the infant's body. Smaller infants, however, cannot tolerate being as upright as larger infants can. Accordingly, the seat shell should be more upright for larger, heavier infants than for smaller, lighter infants.
Some existing car seats include angle indicators to indicate whether the angular orientation of the seat shell is proper when the car seat is situated in a vehicle. Such angle indicators, however, indicate as proper a single range of angular orientations of the seat shell for all infants to which the car seat is suited, and do not differentiate based on the size or weight of the infant. As a result, if the infant occupying the car seat is very large, the angle indicator may indicate as proper a seat shell orientation that is too reclined. Conversely, if the infant occupying the car seat is very small, the angle indicator may indicate as proper a seat shell orientation that is too inclined.